Avoid duplicate closing of fds that correspond to ports.

scsh/newports.scm

@@ -506,7 +506,9 @@
 (define (evict-ports fd)
   (cond ((maybe-fdes->port fd) =>	; Shouldn't bump the revealed count.
          (lambda (port) 
-	   (%move-fdport (%dup fd) port 0)))))
+	   (%move-fdport (%dup fd) port 0)
+	   #t))
+	(else #f)))
 
 (define (%move-fdport fd port new-revealed)
   (obtain-port-lock port)
@@ -529,8 +531,9 @@
   ((if (input-port? port) make-input-fdchannel make-output-fdchannel) fd))
 
 (define (close-fdes fd)
-  (evict-ports fd)
-  (%close-fdes fd))
+  (if (evict-ports fd)
+      #t ; EBADF should not occur if there is a port
+      (%close-fdes fd)))
 
 (define (flush-fdport fdport)
   (check-arg fdport? fdport flush-fdport)